Closing device for flexible tubular packaging

ABSTRACT

A device for closing tubular containers of flexible material, such as sausage casings or the like, contains plate-shaped constricting components for the purpose of forming constrictions in the container and a power-driven device for fastening a closure clip around the constrictions. The closure clip is advanced and pressed against a closing matrix by a punch. The power source for driving the punch and closing the closure clip is fastened to one of the constricting components and can swivel with it, whereby the punch of the device is guided on this constricting component across its entire advance path.

FIELD OF THE INVENTION

The invention relates to a device for closing tubular packagings such assausage casings or the like, with plate-shaped constricting components,which are coupled to a common carrier and can swivel against each other,for closing the packaging tube, and with a punch driven by a powersource as well as with a matrix interacting with it for closing aclosure clip around the braid formed by the constriction of thepackaging tube, wherein in the constricting components both a guidancefeature for the punch is provided, and a matrix is arranged.

BACKGROUND OF THE INVENTION

Such a closing apparatus is known from U.S. Pat. No. 3,717,972. Both thepunch and a double-acting cam plate for swiveling the two constrictingarms serving as constricting components are fastened on the piston of apneumatic cylinder. When the pneumatic cylinder is actuated, the camplate initially swivels the constricting arms, which form a braid of thepackaging tube (which is initially elongated in its cross-section). Atthe same time, appropriately designed sections of the constricting armsextend the guidance provided in the carrier for the punch, so that inthe closed state of the constricting arms, this guidance extends to thematrix that is arranged in one of the constricting arms and the punchcan close the closure clip guided by it around the braid of thepackaging tube with the help of the matrix during an additionaloperating stroke of the pneumatic cylinder.

Such closing apparatuses are employed in particular on machines forstuffing large-sized individual sausages. They are arranged in front ofthe end of the stuffing tube, wherein the respective stuffing tube canbe part of a multiple stuffing head so that during the stuffing processof a sausage, the tubular casing for the next sausage that is to bestuffed can be pulled onto a different similar stuffing tube. Althoughthe processing speed of such stuffing processes is not even close tothat of modern stuffing, portioning and closing machines for theproduction of strings of subsequent sausages, the time factor and themechanical load of the packaging tube play a considerable role.Additionally there is the desire to keep the apparatus-related andoperational efforts, in particular also the wear of the closingapparatus, as low as possible.

SUMMARY OF THE INVENTION

Proceeding from the above-described known closing apparatus, it istherefore the object of the invention to make available a constructionmore favorable both with regard to the construction costs, but above allalso with respect to the costs and reliability during operation.

According to the invention, this task is resolved in that the powersource is fastened on one of the constricting components and can beswiveled with it, and in that the punch is guided in this constrictingcomponent across its entire advance path. The actual closure process isindependent from the prior constriction of the packaging tube. Thelatter occurs preferably by an iris-shaped constricting device, such asthe object of DE-PS 199 34 154.0. Due to the fastening of the powersource for the closure punch to a constricting component, it is pulledalong—the pneumatic cylinder is also suitable for this—during the swivelprocess of the constricting component, and thus simultaneously guidedtowards the braid and the matrix, which is swiveled there with adifferent constricting component, so that only a relatively short strokeof the pneumatic cylinder is required in order to guide the (generallyU-shaped) closure clip around the braid and close it around it with thehelp of the matrix.

The short advance path means not only correspondingly little wear andtear, but above all also reduced consumption of the propellant agent forthe punch closure motion. The advantage of a short-stroke closurecylinder in particular in connection with a stationary closure clipmagazine, which does not swivel along with the punch and its guidancewhen the cylinder swivels, is known from the older patent application199 53 694.5. But there the punch is not integrated in the constrictingunit.

In a beneficial embodiment, the arrangement of a constricting unitconsists of three constricting components, which in each case are seatedon one end on a circle concentric to the axis of the packaging tubeoffset by 120°, in such a way that one of the constricting componentsconsists of a plate and carries the matrix, one consists of twoplane-parallel sheets of metal with a distance that exceeds thethickness of the plate slightly, and the third constricting componentconsists in part of a plate, in part of two plane-parallel sheets ofmetal of that design, wherein the partitioning runs in the middlebetween the two ends of this constricting component and radially to thebearing circle (in the opening state). In this way, both the matrix andthe punch guidance have stable carriers available which, however, canslide between the metal sheets of the respectively other constrictingcomponents with their sections no longer exposed during constriction,and in this way obtain a small thickness of the overall unit.

BRIEF DESCRIPTION OF THE DRAWINGS

Further beneficial embodiments of the invention result from thefollowing description of an example based on the drawings, wherein:

FIG. 1 Shows a front view of a constricting and closing apparatus in the(opened) resting state;

FIG. 2 Provides a view in the direction of line A—A in FIG. 1;

FIG. 3 Gives a view in the direction of line B—B in FIG. 1;

FIG. 4 Represents a view in the direction of line C—C in FIG. 1;

FIG. 5 Depicts a view in accordance with FIG. 1 after transferring aclosure clip from the clip magazine into a state of readiness;

FIG. 6 Provides a similar front view upon closing the constrictingcomponents, and

FIG. 7 Illustrates another similar view upon closing the ready closureclip.

DETAILED DESCRIPTION OF THE INVENTION

The constricting unit of the closing apparatus of the invention,designated as 2 in general, is arranged concentrically to the apertureof a stuffing tube 1, which is only indicated, (added in FIGS. 2-4). Itbasically consists of three plate-shaped constricting components 3, 4and 5, which are seated with one of their ends in a swiveling manner ona stationary carrier ring 6 on pins 7—in each case mutually offset by120°. The other ends of the constricting components 3, 4 and 5 each areseated with sliding blocks 8 in links 9 on a concentrically interiorring 10 in such a way that its rotation leads to a swiveling of theconstricting arms and thus their closure, so that a packaging tubelocated in the opening is gathered into a braid (FIGS. 6 and 7). Inaddition, refer to DE-PS 199 34 154.

The operating areas of all constricting components 3, 4 and 5 thereforehave a (rounded-off) bend of 120° in the center between their ends sothat in the open state of the constricting unit the circumscribedopening takes on the shape of an equal-sided hexagon. The constrictingcomponent 3 consists of a continuous plate 3 a, which in its bent areaaccommodates the matrix 11 with two parallel grooves 12 for the U-shapedclosure clip 20 consisting of wire (FIG. 2). The constricting component5 also half consists of a plate 5 a corresponding to plate 3 a and halfof two plane-parallel metal sheets 5 b, wherein the partitioning seam 5c runs radially in the open state shown in FIG. 1 (FIG. 3). Theconstricting component 4 consists overall of plane-parallel metal sheets4 a in the configuration which can be gathered from FIG. 4 with a crosswall 4 b corresponding to the partitioning seam 5 c. The distancebetween the metal sheets 4 a and/or 5 b exceeds the thickness of theplate sections 3 a and/or 5 a slightly so that upon swiveling theconstricting components and closing the constricting unit, the latterfind room between the first (FIGS. 6, 7).

In the plate section 5 a of the constricting component 5, the guidance13 for the punch 14 of the closing apparatus, designated overall with15, is provided (FIGS. 3, 1). The punch guidance 13 is, as clearly shownin FIG. 3, slightly swiveled so that during the closure process, the oneleg of the U-shaped closure clip 20 reaches into the one groove 12 andthe other leg in the other groove 12 of the matrix 11, resulting in aspiral-shaped closure state of the clip.

The punch 14 is fastened to the piston 16 of a pneumatic cylinder 17,which is fastened in turn on a flange 5 d of the constricting component5. The pneumatic cylinder 17 is constructed as a step cylinder with acylinder section 17 a of smaller diameter, whose piston 16 a has aconnecting action to the piston 16. Through a cut-out section 18 in theflange 5 d, a stationary magazine 19—for example held on the supportring 6—extends for the supply of closure clips 20. This is not visiblein FIGS. 1 and 5, but in FIGS. 6 and 7 because there the constrictingcomponent 5, which is swiveled with the pneumatic cylinder 7, exposesthe view to that area.

In the starting position shown in FIG. 1, the magazine 19 is connectedwith the closure clips 20 located on it via an intake opening (notshown) of the punch guidance 13 so that a closure clip 20 can enter theclip advance channel formed by this guidance. By initially acting onlyon the piston 16 a in the cylinder section 17 a, the punch 14 isadvanced and guides the clip 20 in its ready state (shown in FIG. 5)within the punch guidance 13. This way, by rotating the rings 6 and 10against each other, the constricting components 3, 4 and 5 are broughtinto their closed constricting position shown in FIG. 6 while swivelingthem about their swivel pins 7. The braid (not represented here) of thetubular packaging casing is located in the resulting, roughly triangularopening (FIG. 6) then remaining. As FIG. 6 makes clear, in thisconstricting process simultaneously the matrix provided in theconstricting component 3 on one hand and the closure clip 20 availablein the constricting component 5 on the other hand were guided towardsthe opening 21. The section 18 in the flange 5 d of the constrictingcomponent 5 thus prevents an impairment of the swivel process by themagazine 19 with the closure clips 20 located thereon. Finally, byaction of the piston 16, the closure clip is guided around the braid ofthe packaging casing located in the opening 21 into the grooves 12 ofthe matrix, and the closure clip 20 is closed in its conventional way bybending of the legs. The punch 14 then moves back into its startingposition and the constricting components 3, 4 and 5 are also swiveledback into their open positions in accordance with FIG. 1.

1. An apparatus for closing tubular containers of flexible material,with a clip, the apparatus comprising: a carrier having an opening forthe passage of a container of flexible material; a plurality ofconstricting components pivotally mounted on the carrier and pivotallymovable toward each other and into engagement with such a container atthe opening for constricting the container and providing a containerconstriction; a clip guide mounted on one of the plurality ofconstricting components for guiding clips to the container constriction;a matrix mounted on another of the plurality of constricting componentsfor receiving and closing a clip at the container constriction; a punchmounted on said one of the constricting components and which can beadvanced along a path for engaging and moving a clip toward theconstriction and into engagement with the matrix and thereby closing theclip on the constriction; and a power source mounted on and movable withsaid one of the constricting components and coupled to said punch formoving said punch into engagement with a clip and pressing the clip intoengagement with the matrix.
 2. An apparatus as set forth in claim 1wherein there are three said constricting components.
 3. An apparatus asset forth in claim 2 wherein the carrier is a ring having an axis andhas said opening concentric with said axis.
 4. An apparatus as set forthin claim 3 wherein pivoting of said one component and of anotherconstricting component moves the matrix and the punch path intoalignment.
 5. An apparatus as set forth in claim 3 wherein theconstricting components have opposite ends and are pivotable at one endaround pivots on the ring and disposed 120° apart on a circle concentricwith said axis.
 6. An apparatus as set forth in claim 5 wherein the ringis rotatable around said axis and further comprising closing meansmounted on the ring and engageable with the other ends of theconstricting components for moving the constricting components intoengagement with the container with rotation of the ring.
 7. An apparatusas set forth in claim 5 wherein a first one of the constrictingcomponents comprises a plate and the matrix is mounted thereon, a secondone of the constricting components comprises, in part, a plate and inpart, two plane-parallel sheets and a third one of the constrictingcomponents comprises two plane-parallel sheets spaced perpendicular tothe planes of the sheets of the third one of the constricting componentsby a distance at least equal to the thicknesses of the plates of thefirst one and the second one of the constricting components to provideinterleaving of the constricting components as the components are movedtoward each other.
 8. An apparatus as set forth in claim 7 wherein thetwo plane-parallel sheets of the second one of the constrictingcomponents adjoins the plate of the second one of the constrictingcomponents which provides a partition where the sheets and the plateadjoin and wherein, prior to movement of the constricting componentstoward each other, the partition has a face which extends radially ofsaid axis.
 9. An apparatus as set forth in claim 7 wherein the punch ismounted on the second one of the constricting components.
 10. Anapparatus as set forth in claim 7 wherein said first one of theconstricting components and said second one of the constrictingcomponents have surfaces which face said axis and each of which has twoparts which intersect at an obtuse angle included between the parts andwherein the matrix is disposed at the intersection of the two parts ofthe surfaces of said first one of the constricting components and thepath of the punch passes through the intersection of the two parts ofthe surfaces of said second one of the constricting components.
 11. Anapparatus as set forth in claim 1 wherein the carrier is rotatablearound an axis concentric with said opening in the carrier.